"Russell has been playing pain free, but recently had experienced increased swelling," Thundergeneral manager Sam Presti said in a statement. "After consultation and consideration by his surgeon in Los Angeles, a plan was established to monitor the swelling that included a series of scheduled MRIs.

"On the most recent MRI it was determined by the surgeon that there was an area of concern that had not previously existed, nor was detectable in the previous procedures, and it was necessary to evaluate Russell further. The consulting physician determined that arthroscopic surgery was necessary to address the swelling that was taking place. We know that Russell's work ethic and commitment will help him return to the level of play that we have all come to appreciate."